Drill bit



F. l PIVOTO Sept. 20, 1932.

DRILL BIT Filed March 15, 1951 'A pnl ieationfiled March-1 13, 11331.1 j s iia V This invention relates to a novel typefof -dri1lbit.--- a a I One object of the/"invention is to provide a drill bit of the character described having a novel type of bithe'ad withradial blades of novel formation arrangedthereon. 1

a Another object of the inventionis'to proyidea bit'of the character described having V vide a bit ofthe characterdescribed having a novel arrangement of dischargeopenings 7 blades. 7

a head with radial blades formed(integrallyv therewith '1 and arranged 'a jnovel m nne on the head. M

for discharging, flushing unto the With the above: and otherobjects iniview,

v theinvention has particular relation to cers :tain'novelfeatures of construction, arrangementof parts and use, an exampleofwhich is given in this specification and illustrated in the; accompanying drawing, whereini V Figurel shows a? side View of the bit. a l i Figure 2 shows a vertical "sectional View,

and V r W -Figure3 shows a bqttom end View. Referring now more particularly" to the drawing, wherein like numerals of refer'ence designate similar part'sineach of the figures,

the numeral 1 designates thehead which is 7 of shell like formation and whose lower end? is oval. Thehead hasthe internallyjthreaded tapering box 2r-int'o which' the lowerend'of the drill stemmay be screwed. This lowerend usually has" a drill fcollar having an ex-l] V ternally threadedtapering pinf to bescrewed into-said box. The-upper endl 'f the head is' reinforced or thickened asat 3iforstrength;

Leading out from the lower "end loff'the box 2 there isawater course'l which is arranged eccentrlc than the ibla d'e" "t at ,mayhel t bet with respect to the 1 verticalaxisofthehead.I; f' Eblmed integrally. with the. head there are thera-dial'blades5, 6,7 whichare preferably spaced a uniform distance {apart around thejhead. .f-These bladesextend later ally beyond the head and project-downwardly beneath the lower end of: the head as shown; "The lower ends of the bladesare forwardly; curved andjformed with sharpcutting edges these bladesyin a ATE-S; m

L'.T-r'1vo'ro; t eatm nt if-Exes 8;.9;102-zr il wegend ar each bladeisprovided; with a yerticalj sl'ot, said slots being h .dt 'i ae s fib 66 I I V i the-Qbl-ade-G' and the. blade 6 'l QmeWh ii "th l tli jb d similfa r" progressive manner extendi'out rfurtherbeyond the'head thanfithef njext succeedingronei:inffronfi that a r I is sa th b a efi Another objectofitheinventionfis to pro? somewhat 'furtherithan-fthe bladeb and? the blade' fi extend out fflonf the "head further inwardly to a -Point near theye'rti'cal "axis of inwardly a distance; somewhat less .than thatofithe blade- 6;

The blade 5, also 'extends f the head andthe inner margin of the blade tiextends inwardly, a distancesoniewh'at less n" bit to progressively widen theabore as drilling the bladsii=2 -.I n1 front of theblades 13, 12 are thefiushingiwater channels14,15, 16 respectively, said channels beingarran'gedprogres-Q sivelyout further from the vertical axis of the-'head,that is the cl'iannel 15 is "out some-' v is whatfurtherjfrom saidaxisthan the channel" 81 from the axis than the channel 15. The H: water flushed through these channels will not i I i only provide flushing fluid for the blades but] 14 and the channel 16 is out somewhat; further will wash out the slots 11,12, 13 and keep the same cleansed. Furthermore the flushing.

channels 4, :14, 15,16 leading out fromi the j box 2 will'be .,comparatively short and will 1 notbe liableto' become blocked up with the," j formation butjwillalways be open to permit I -The;drawin'g anddescription disclose what the free flow of the flushingfiuid'.

is now considered to be fa preferred form of e i ve y Way of "illustration" only I while} the broa'dprinciple of theinventi 0 wiu defin edbyithe appended claims/ P progressesiandith bit;wi1l 1eave substan ti ally "nolcjentralcore" of the formationi The 5 flushing-fluid discharged'ithrough' the open V ing i' w'il-l wash awaylandjdestroydany core i be inner margins of,

Thisfarran-gement of blades will cause: the

What I claim is: v 1. A drill bit comprisinga head, a series of radial blades on the lower end ofthe head terminating at their lower ends in cutting edges, each blade having a vertical slot, said slots being arranged progressively out at different distances from the axis of the head, said head having channels for flushing fluid 1 which terminate opposite said slots.

1O 2. A drill comprisinga shell-like head hav ing an internally threaded box at its upper c end, a series of radial cutting blades integral with the sides and lower end of head which extend out laterally beyond the head and are 5 extended beneath the head, "said blades each having a vertical slot in its lower end, said slots being arranged progressively outward at-dilferent distances from the axis of the head, said head having channels leading downwardly from said box through the lower end of the head and terminating in front of said respective blade slots. V a 3. A drill comprising a shell-like head having an'internally threaded box at its upper 26 end, a series of radial cutting blades on the head which extend out laterally beyond the head and are extended beneath the head, one blade of said series being wider than the V other blades, and said other blades being prov 30 gressively narrowed, said blades each having a vertical slotin its lower end, said head hav- 1 ing channels leading downwardly from said box through the lower end, of the head and terminating in front of said respective blade 7 slots and said head also having a channel of the head from said box andterminating ec centrically with respect to the vertical axis of V the head and being located between the inner edges of the blades. In testimony whereof I have signed my name to this specification.

- FELIX L. PIVOTO.

so V

leading downwardly through the lower end l I V 

